If your HSN is screwed out 2 1/2 turns from flush you are running way to rich. You will need to screw your HSN in all the way untill it slightly bottoms out and then screw it out 2 1/2 turns.
The LSN you might want to screw in 1 to 1 1/2 turns from flush. These settings might be a little to lean for you weather conditions but the truck should run on them. I would also put in a new OS A5 glow plug.

There is also a possibility that it is time for a rebuild.



rolland